Communication system, mobile communication terminal and position managing apparatus

ABSTRACT

A mobile node includes a plurality of transceivers, has a network conforming to network-based mobility as its home link and performs position registration to a positional managing apparatus and performs position registration to the position managing apparatus through a foreign network by position registration conforming to host-based mobility. In mobile node and position managing apparatus, a plurality of routes passing through the home link and the foreign link are established. Accordingly, when the mobile node has the plurality of transceivers, it can simultaneously connect to the home link and the foreign link through respective transceivers, to perform communication.

CROSS-REFERENCE

This application is a Divisional of copending application Ser. No.14/805,288, filed on Jul. 21, 2015; which is a Continuation ofapplication Ser. No. 12/532,556, filed Sep. 22, 2009, issued on Aug. 18,2015 as U.S. Pat. No. 9,113,435; which was filed as a 371 Application ofPCT International Application No. PCT/JP2008/055269 on Mar. 21, 2008,which claims the benefit under 35 U.S.C. §119(a) to Japanese PatentApplication No. JP2007-077908, filed in Japan on Mar. 23, 2007, all ofwhich are hereby expressly incorporated by reference into the presentapplication.

TECHNICAL FIELD

The present invention relates to a communication system or the like,including: a mobile communication terminal that includes a plurality oftransceivers and connects through the transceivers to a home link thatis constructed of a network performing network-based mobile managementand a foreign link; and a position managing apparatus for managing theposition of the mobile communication terminal.

BACKGROUND ART

In the internet, network-based mobility (see non-patented document 1,for instance) and host-based mobility (see non-patented document 2, forinstance) have been known as the technologies that offer IP-layermobility of a node to permit its continuation of communication withanother node at the opposite communication end even if the node changesits connection from one link to another as it moves.

For example, Proxy Mobile IPv6 (PMIPv6, hereinbelow) as thenetwork-based mobility disclosed in non-patented document 1 sets up aPMIP network for the network, to which a mobile node is connected, andin which an access gateway (PMA: Proxy Mobile Agent) as a default routerfor the mobile node and a position managing apparatus (HA: Home Agent)for managing the PMA to which the mobile node attaches itself aredefined.

The HA assumes the PMA to which the mobile node is connected as thepositional information of the mobile node and manages the identificationinformation on the mobile node in association with the identificationinformation on the PMA. In the HA, the PMA to which the mobile node isconnected is continuously updated as the mobile node moves so as tomaintain the positional information.

The mobile node has a unique IP address which identifies itself andtransmits a packet to the PMIP network by designating the IP address forthe receiver and sender of the packet to be communicated between mobilenodes. The PMA to be the point of connection of the mobile node in thecore network forwards the packet to the HA. The HA determines the PMA towhich the destination mobile node is attached, based on the positionalinformation and forwards the packet.

Accordingly, inside the PMIP network, a forwarding route is establishedbetween the HA and the PMA so that the packet is conveyed between mobilenodes by packet forwarding.

In PMIPv6, the mobile node continues communication by only changing thePMA as a default router as the mobile node moves. Inside the PMIPnetwork, the positional information is updated in the PMAs and HA so asto perform packet forwarding to thereby realize communication betweenmobile nodes. The mobile node continues communication by changing PMAsas it moves, but it can continue using the unique address if it connectsto any PMA. This makes it possible to minimize the movement process tobe effected by the mobile node and brings about the advantage that thenumber of control signals can be reduced in the wireless section.

On the other hand, non-patented document 2 describes Mobility Support inIPv6 (MIPv6 hereinbelow) as one example of host-based mobility. MIPv6defines a mobile node that changes the point of connection to thenetwork with moving and a position managing apparatus (HA: Home Agent)for performing positional management of the mobile node.

A mobile node holds a unique and unvaried IP address that identifiesitself on the network, and uses it as the receiver and sender of atransmitted/received packet in communication between mobile nodes.Further, the mobile node acquires an address on a visited network andthe acquired address is registered as its positional information to theHA. In the HA, the IP address that identifies the mobile node and the IPaddress acquired at the visited site for identifying the position aremanaged in association with each other.

The packet which the mobile node sends out to another mobile node isforwarded by the HA based on the address acquired at the visited site.Specifically, the packet which mobile node 1 transmits to mobile node 2is forwarded to the HA by tunneling the IP packet having the address ofmobile node 1 acquired at the visited site set as the sender and the HAset as the receiver. The HA solves the positional information of mobilenode 2 on the receiver side and forwards the transmission packet to theaddress of mobile node 2 acquired at the visited site, by tunneling theIP packet having the HA set as the sender and the address of mobile node2 acquired at the visited site set as the receiver. The packets betweenmobile nodes are delivered in the above way.

In the internet, it was conventionally impossible for a terminal tocontinue communication by changing its connection point, but theaforementioned PMIPv6 and MIPv6 have enabled a mobile node to continuecommunication using a single IP address even if the mobile node changesits network connection point.

In PMIPv6 and MIPv6, a mobile node can move while changing itsconnection point. However, it is impossible for a mobile node to have aplurality of transmitter-receivers and establish connection to networksat the same time. In order to solve this problem, Multiple Care-ofAddresses Registration (MCoA hereinbelow) (see non-patented document 3,for instance) has been defined.

In MCoA, the mobile node includes a plurality of transmitter-receivers,which each register an address obtained from the networks to which theyconnect, as their positional information, to the HA. A series ofregistering procedures is expanded based on MIPv6. The difference fromMIPv6 is that the mobile node registers plural positional informationaddresses to the HA and that the HA and the mobile node have a pluralityof packet delivery routes. The HA and the mobile node can transmit apacket using a delivery route selected based on the type of the packetor preferences when the packet is delivered.

-   Non-patented document 1: S. Gundavelli, et al., “Proxy Mobile IPv6”,    draft-sgundave-mip6-proxymip6-01, January 2007;-   Non-patented document 2: D. Johnson, et al., “Mobility Support    inIPv6”, RFC 3775, June 2004; and-   Non-patented document 3: R. Wakikawa, et al., “Multiple Care-of    Addresses Registration”, draft-ietf-monami6-multiplecoa-01.txt,    October 2006.

DISCLOSURE OF INVENTION Problems to be Solved by the Invention

In the case where a network that supports network-based mobility and anetwork that supports host-based network base coexist and a mobile nodemoves between these networks, the system is constructed of PMIPv6 andMIPv6 schemes in combination, as shown in FIG. 20.

The HA for PMIPv6 and the HA for MIPv6 are provided in an identicalapparatus so that the movement between the PMIP network and the foreignnetwork is managed based on MIPv6 and the movement inside the PMIP ismanaged based on PMIPv6. When the mobile node moves changing its PMAinside the PMIP network, the mobile node performs communication usingthe MIPv6 home address. When the mobile node moves to the foreignnetwork outside the PMIP network, the mobile node registers its positionto the HA using its care-of address obtained in the foreign network tocontinue communication.

A PMIP network is characterized in that a mobile node receives the samenetwork information if it connects to any of the PMAs on the PMIPnetwork, so as to continue communication using a single address. Inother words, this is a method of managing movement of a mobile nodeinside the PMIP network so as to hide movement to a terminal. A PMIPnetwork can be made large in scale by a trader that manages networks.For example, a communication carrier constructs a large-scale PMIPnetwork that covers all over Japan, and the subscriber terminal cancontinue communication by connecting to any of the PMAs using a singleaddress.

On the other hand, as a foreign network on which movement managementbased on MIPv6 is needed, a hot spot that uses an access system such asa WLAN or the like implemented by a trader different from thecommunication carrier that operates the PMIP network can be presumed.Under these circumstances, a mobile node can connect to them byincluding both the transmitter-receiver for accessing the communicationcarrier network and the transmitter-receiver for accessing the hot spot.

Since in the large-scale communication carrier network, or the PMIPnetwork, a mobile node can behave as a mere IP node without any need ofmovement management, it is preferred that the PMIP network is the homelink defined based on MIPv6. That is, the HA of PMIPv6 enables themobile node to perform communication with the home address by managingthe PMA which the mobile node connects to, as its positionalinformation.

Further, when the mobile node moves from the PMIP network to the foreignnetwork, it moves from the home link defined by MIPv6 to the foreignlink. Movement management is performed by the HA, which managescorrespondence between the home address of the mobile node and itscare-of address, to continue communication.

Accordingly, when the mobile node includes a plurality of transceiversand connects to both the PMIP network and the foreign networksimultaneously through respective transceivers, the mobile node realizessimultaneous connection to the home link defined by MIPv6 and theforeign link.

A method for a mobile node based on MIPv6 including a plurality oftransceivers to perform simultaneous connection to the networks throughrespective transceivers is defined by MCoA. However, this method couldpermit only the connection shown below and could not permit simultaneousconnection to both the home link and the foreign link.

(1) Of the connections through a plurality of transceivers, when oneconnects to the home link, only the transceiver that connects to thehome link is used to continue communication without use of thetransceiver that connects to the foreign link.

(2) Of the connections through a plurality of transceivers, when oneconnects to the home link, only the transceiver that connects to theforeign link is used to continue communication without use of thetransceiver that connects to the home link.

Accordingly, when a PMIP network is employed as the home link andsimultaneous connection to the home link and the foreign link is tried,it has been impossible for the mobile node to achieve simultaneousconnection by using MCoA.

This limitation is caused by the function that the HA receives thepacket that is addressed to the mobile node, in MIPv6 and MCoA. For theHA, two methods of installation as shown in FIGS. 21(a) and (b) aredefined.

In FIG. 21(a), the HA has a position managing function and also servesas a border router in the home link so as to be connected to the foreignnetwork. In FIG. 21(b), the HA has a position managing function but aseparate border router for home link is installed to be connected to theforeign network.

A packet transmitted to a mobile node from a communication terminalconnected to the foreign network is transmitted to the boarder router ofthe home link by the routing scheme of the conventional internet. Whenthe mobile node connects to the foreign link, the HA receives the packetin place of the mobile node and forwards it to the visited site. Whenthe mobile node is connected to the home link, the mobile node in thehome link receives the packet without intermediary of the HA.

In order for the HA to receive the packet instead of the mobile node,the HA uses a function called ProxyNDP. ProxyNDP is a HA's functionwhich announces the fact that HA will receive a packet addressed to themobile node to the home link so as to receive the packet. The HAreceives packets by ProxyNDP only when the mobile node is out and makesthe ProxyNDP function invalid when the mobile node has returned to thehome link so that the mobile node can receive the packets.

As a result, even in the case where the HA does not serve as a borderrouter as shown in FIG. 21(b), the HA can initially receive the packetaddressed to the mobile node, which the boarder router routed to thehome link and can forward it to the visited site.

Accordingly, there has been the problem that the mobile node cannotreceive the packet in the home link if the HA sets the ProxyNDP functionvalid. On the other hand, when HA sets the ProxyNDP function invalid,there is the problem that the mobile node can receive the packet at thehome link but the HA cannot receive packets temporarily.

In MCoA, when the mobile node connects to its home link through one ofplural transceivers and connects to the foreign link through the othertransceiver, it is necessary to perform reception at the transceiverconnected to the home link, and reception of the packet once received bythe HA and forwarded to the foreign link, at the transceiver connectedto the foreign link. However, there has been the problem that thiscannot be realized because of the aforementioned ProxyNDP limitation.

In view of the above problems, it is therefore an object of the presentinvention to enable a mobile node including a plurality of transceiversto perform communication by its simultaneous connection to the home linkand foreign link through the respective transceivers.

Means for Solving the Problems

In view of the above problems, a communication system of the presentinvention, includes: a mobile communication terminal including aplurality of transceivers and connecting through the transceivers to ahome link that is constructed of a network performing network-basedmobile management and a foreign link; and a position managing apparatusfor managing a position of the mobile communication terminal, and ischaracterized in that the mobile communication terminal includes aposition registering means for registering positional informationthereof in the network to which the mobile communication terminalconnects, into the position managing apparatus, the position managingapparatus includes: a packet transmitting and receiving means forreceiving a packet addressed to the mobile communication terminal andtransmitting a packet to be transmitted from the mobile communicationterminal; a packet destination determining means for determining adestination of the packet from the packet received by the packettransmitting and receiving means; and, a positional information storingmeans for storing the positional information registered by the positionregistering means in association with the mobile communication terminal,and, the packet transmitting and receiving means determines a positionof a receiver as the destination determined by the packet destinationdetermining means, from the positional information storing means totransmit the packet.

Also, the communication system of the present invention is characterizedin that the mobile communication terminal simultaneously connects to thehome link through one transceiver and the foreign link through anothertransceiver.

Further, the communication system of the present invention ischaracterized in that the positional information storing means stores aplurality of positional information corresponding to the mobilecommunication terminal, and the packet transmitting and receiving means,when receiving the packet addressed to the mobile communicationterminal, selects one positional information from the positionalinformation stored by the positional information storing means andtransmits the packet by determining a route based on the selectedpositional information.

Moreover, the communication system of the present invention ischaracterized in that the position registering means registers thepositional information of the mobile communication terminal in the homelink and the positional information in the foreign link, individually.

Still more, the communication system of the present invention ischaracterized in that the mobile communication terminal is assigned witha home address, the positional information includes an address of arouter to which the mobile communication terminal connects in the homelink or an address acquired by the mobile communication terminal in theforeign link, and the mobile communication terminal further includes: anaddress storing means for storing the address and the home address ofthe mobile communication terminal in a related manner; a packet creatingmeans for creating a packet by determining an address to be a sender,from the address storing means, in association with the network throughwhich the receiver of the packet passes; and a packet transmitting meansfor transmitting the packet created by the packet creating means.

A mobile communication terminal of the present invention, includes aplurality of transceivers and connecting through the transceivers to ahome link that is constructed of a network performing network-basedmobile management and a foreign link, and is characterized in that themobile communication terminal is assigned with a home address, andperforms communication based on an address storing means for storing anaddress of a router to which the mobile communication terminal connectsin a home link and an address acquired by the mobile communicationterminal in a foreign link, in association with a home address of themobile communication terminal, a route determining means for determininga route of communication, a selecting means for selecting an addressassociated with the home address of the mobile communication terminalstored in the address storing means, in accordance with a networkthrough which the communication route determined by the routedetermining means passes, and the address selected by the selectingmeans.

Also, the mobile communication terminal of the present invention ischaracterized in that it simultaneously connects to the home linkthrough one transceiver and the foreign link through anothertransceiver.

The position managing apparatus resides in a position managing apparatusfor managing the position of a mobile communication terminalindividually connected to a home link that is constructed of a networkperforming network-based mobile management and a foreign link,comprising: a positional information storing means for storingpositional information of the mobile communication terminal; a means fortransmitting and receiving a packet addressed to the mobilecommunication terminal and a packet transmitted from the mobilecommunication terminal; and, a packet destination determining means fordetermining a destination of a packet, from the packet received by thepacket transmitting and receiving means, and is characterized in thatthe packet transmitting and receiving means determines a position of thedestination determined by the packet destination determining means, fromthe positional information storing means and transmits the packet.

Also, the position managing apparatus of the present invention ischaracterized in that the positional information storing means stores aplurality of positional information corresponding to the mobilecommunication terminal, the packet transmitting and receiving means,when receiving a packet addressed to the mobile communication terminal,selects one positional information from the positional informationstored by the positional information storing means and transmits thepacket by determining a route based on the selected positionalinformation.

Advantage of the Invention

According to the present invention, in the communication systemincluding: the mobile communication terminal including the plurality oftransceivers and connecting through the transceivers to the home linkthat is constructed of the network performing network-based mobilemanagement and the foreign link; and the position managing apparatus formanaging the position of the mobile communication terminal, the positionmanaging apparatus, when receiving a packet, determines the position ofthe receiver of the packet based on the positional information storingmeans stored in the position managing apparatus and sends the packet.Here, when a PMIP network is employed as the home link, the positionmanaging apparatus will be able to transmit the packet appropriately tothe receiver terminal either by way of the PMIP network or by way of theforeign network.

Also, according to the present invention, it is possible for the mobilecommunication terminal to connect to the home link and the foreign link,at the same time. Accordingly, the mobile communication terminal is ableto perform communication at any time by way of either of the networks.

Further, according to the present invention, in the mobile communicationterminal including a plurality of transceivers and connecting throughthe transceivers to the home link that is constructed of the networkperforming network-based mobile management and the foreign link, theaddress of the router to which the mobile communication terminalconnects in the home link and the address acquired by the mobilecommunication terminal in the foreign link are stored in associationwith the home address assigned to the mobile communication terminal.With this, one address that is associated with the home address of themobile communication terminal is selected in accordance with the networkthat the communication route passes through, to perform communication.Upon this, the mobile communication terminal is connected to the homelink by way of one transceiver and connected to the foreign link by wayof another transceiver, to achieve simultaneous connect to the home linkand the foreign link.

Moreover, according to the present invention, the position managingapparatus stores the plurality of positional information for the mobilecommunication terminal into the positional information storing means.Accordingly, when a packet is transmitted to the mobile communicationterminal, it is possible to determined the route based on the positionalinformation stored in the positional information storing means andtransmit the packet.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 A diagram showing the outline of a communication system.

FIG. 2 A diagram showing one exemplary configuration of a mobile node.

FIG. 3 A diagram showing one example of the data structure of an addressmanagement table.

FIG. 4 A diagram showing one exemplary configuration of a PMA.

FIG. 5 A diagram showing one example of the data structure of anattachment node management table.

FIG. 6 A diagram showing one exemplary configuration of a positionmanaging apparatus.

FIG. 7 A diagram showing one example of the data structure of apositional information management table.

FIG. 8 A sequence diagram in a position registering process.

FIG. 9 An operation flow chart showing the operation of a mobile node.

FIG. 10 An operation flow chart showing the operation of a mobile node.

FIG. 11 An operation flow chart showing the operation of a positionmanaging apparatus.

FIG. 12 A diagram showing the scheme of a communication system.

FIG. 13 A sequence diagram showing packet forwarding.

FIG. 14 A diagram showing one example of a packet format.

FIG. 15 A diagram showing one example of a packet format.

FIG. 16 An operation flow chart showing the operation of a mobile node.

FIG. 17 An operation flow chart showing the operation of a positionmanaging apparatus.

FIG. 18 A diagram for illustrating a variational example in theembodiment.

FIG. 19 A diagram for illustrating a variational example in theembodiment.

FIG. 21 A diagram for illustrating a conventional communication system.

DESCRIPTION OF REFERENCE NUMERALS

-   10 access router (AR)-   20 mobile node-   200 processor-   202 first transceiver-   204 second transceiver-   206 storage-   2062 address management table-   208 PMIPv6 processor-   210 MIPv6 processor-   212 packet transmitter-   30 PMA-   300 processor-   302 wireless transceiver-   304 wired transceiver-   306 storage-   3062 attachment node management table-   308 PMIPv6 processor-   310 packet forwarder-   40 position managing apparatus (HA)-   400 processor-   402 PMIP network transceiver-   404 foreign network transceiver-   406 Storage-   4062 positional information management table-   408 PMIPv6 processor-   410 MIPv6 processor-   412 packet forwarder

BEST MODE FOR CARRYING OUT THE INVENTION

Now, the best example of a packet communication system in the case towhich the present invention is applied will be described using thedrawings.

1. Configuration 1.1 Network Configuration

To begin with, the packet communication system in the present exemplaryembodiment is constructed of networks conforming to network-basedmobility and host-based mobility, and has a configuration that canconnect to a PMIP network as the home link and a foreign network as theforeign link at the same time, as shown in FIG. 1.

Further, the position managing apparatus (Home Agent: HA) for performingpositional management of mobile nodes in each network is comprised of asingle apparatus. In the PMIP network as a network-based mobilitynetwork, a plurality of PMAs (Proxy Mobile Agents) serving as defaultrouters for mobile nodes and forwarding packets to position managingapparatus are deployed. In the foreign network as a host-based mobilitynetwork, a plurality of ARs (Access Routers) serving as default routersand distributing addresses to be acquired at the connection points ofmobile nodes are deployed.

In the drawings, a PMA 30 is provided in the PMIP network and an AR 10is provided in the foreign network. Further, in the PMIP network, an HA40 is provided as the position managing apparatus. Connected to theforeign network is a communication device to be the opposite end fromthe mobile node.

A mobile node 20 shown in FIG. 1 is assigned with “HoA(P1::MN1)” as itshome address. It is also assigned with “CoA(P2::MN1)” as its care-ofaddress when it connects to the foreign network.

Here, for description convenience, FIG. 1 shows only one AR 10, mobilenode 20 and PMA 30 as each device, but multiple devices may, of course,be deployed.

Here, one example of the network-based mobility network may be acellular network which a communication carrier that operates to connectcellular phones, a carrier's network for operating an ISP, or the like.Further, one example of the foreign network for supporting movementbased on host-based mobility may be a WLAN, home network, or a carriernetwork operated by another carrier.

1.2 Mobile Node Configuration

Next, the configuration of mobile node 20 will be described. Mobile node20 is a mobile terminal that makes simultaneous connection to aplurality of network accesses such as a cellular mobile terminal, PDA,etc. having mobile node functionality conforming to PMIPv6, MIPv6 andMCoA. It also has the function of establishing simultaneous connectionto its home link which is a network-based mobility network and a foreignlink which is a host-based mobility network.

Here, mobile node 20 includes, as shown in FIG. 2, a processor 200, afirst transceiver 202, a second transceiver 204, a storage 206, a PMIPv6processor 208, an MIPv6 processor 210 and a packet transmitter 212.

Processor 200 is a functional part for controlling mobile node 20, orthe functional part executing processes based on a predetermined programto transmit commands and data to diverse functional parts. For example,processor 200 is constructed of a CPU (Central Processing Unit) and thelike.

First transceiver 202 and second transceiver 204 are each connected toan external antenna, and transceivers for establishing wirelessconnection to a network. The transceivers perform transmission andreception of packets via respective networks. As the wireless accessingtechnique for first transceiver 202 and second transceiver 204 toachieve wireless connection herein, any technology such as a wirelessaccess system used in wireless LANs, cellular networks, a short-distancewireless access system such as Bluetooth (registered trademark) etc.,and the like can be used.

Storage 206 is a functional part for storing various kinds of data andprograms, in particular, includes an address management table 2062.Address management table 2062 is a table for storing default data forconnection based on PMIPv6. It also stores the care-of address asconnection information for connection to a foreign network based onMIPv6, the HA address and default router information.

Here, FIG. 3 shows one example of the data configuration of addressmanagement table 2062. Herein, an address as positional information, adefault router and a position managing apparatus are stored in a relatedmanner. For example, for the home address (HoA) “P1::MN1”, “PMA 30” isassociated as the default router for connection based on PMIPv6 and acare-of address (CoA)“P2::MN1” is associated to connect based on MIPv6.Further, for care-of address (CoA)“P2::MN1”, “AR 10” is stored as thedefault router and “HA 40” is stored as the position managing apparatus.

Packet transceiver 212 selects either first transceiver 202 or secondtransceiver 204 based on address management table 2062 stored in storage206 and sends out a packet therethrough. Further, it receives a receivedpacket from each transceiver.

MIPv6 processor 210 is a functional part for performing an MIPv6 processwhen connection from the PMIP network to the foreign network isimplemented. Further, PMIPv6 processor 208 is a functional part forperforming transmission and reception of an attachment request and replywhen connection to the PMIP network is performed.

1.3 PMA Configuration

Next, the configuration of a PMA 30 in the present embodiment will bedescribed. PMA 30 is an apparatus constructed conforming to PMIPv6.

As shown in FIG. 4 PMA 30 includes a processor 300, a wirelesstransceiver 302, a wired transceiver 304, a storage 306, a PMIPv6processor 308 and a packet forwarder 310. Further, an external antennafor communications is connected to wireless transceiver 302.

Processor 300 is a functional part for controlling PMA 30, or thefunctional part executing processes based on a predetermined program totransmit commands and data to diverse functional parts. For example,processor 300 is constructed of a CPU (Central Processing Unit) and thelike.

Wireless transceiver 302 is a transceiver for establishing wirelessconnection to mobile node 20 and performs transmission and reception ofpackets. As the wireless accessing technique for wireless connection,any of a wireless LAN, a wireless access system used in cellularnetworks and a short-distance wireless access system such as Bluetooth(registered trademark) etc., can be used.

Wired transceiver 304 is a transceiver that is connected by wire to arouter or a switch inside the PMIP network, and is a functional part forperforming transmission and reception of packets. As the accessingtechnique for wired connection, widely used Ethernet (registeredtrademark) or the like can be used.

Storage 306 is a functional part for storing various kinds of data andprograms, in particular, includes an attachment node management table3062. Attachment node management table 3062 stores attachment mobilenodes and their correspondent forwarding positions (addresses).

Here, FIG. 5 shows one example of the data configuration of attachmentnode management table 3062. Herein, attachment nodes are stored inassociation with forwarding positions. For example, “mobile node 30” andthe forwarding position of mobile node 30, “HoA(P1::MN1)” are stored inassociation with each other.

The forwarding designation of nodes that have not been registered inattachment node management table 3062 are registered as “the others”.For example, in the case of FIG. 5, a packet of a node that has not beenregistered in attachment node management table 3062 will be forwarded to“HA 40”.

PMIPv6 processor 308 is a functional part that notifies HA 40 of theidentification information on mobile node 20 and the identificationinformation on PMA 30. Further, the PMA registers into attachment nodemanagement table 3062 in storage 306 the fact that the mobile node hasattached to itself. Further, the PMA makes a reply to the attachmentrequest to the mobile node.

With this configuration, the mobile node can register its position to HA40 when the mobile node has attached to PMA 30. Further, it is possibleto determine the delivery address of the packet addressed to theattached mobile node.

Packet forwarder 310 is a functional part for forwarding packets basedon attachment node management table 3062. For example, based on theattachment node management table 3062 shown in FIG. 5, a packet tomobile node 30 will be forwarded to the address of “HoA(P1::MN1)”.

1.4 HA Configuration

Next, HA 40 in the present embodiment will be described. As shown inFIG. 6, HA 40 includes: a processor 400; a PMIP network transceiver 402for connection to the PMIP network; a foreign network transceiver 404for connection to a foreign network; a storage 406; a PMIPv6 processor408; an MIPv6 processor 410; and a packet forwarder 412.

Processor 400 is a functional part for controlling HA 40, or thefunctional part executing processes based on a predetermined program totransmit commands and data to diverse functional parts. For example,processor 400 is constructed of a CPU (Central Processing Unit) and thelike.

PMIP network transceiver 402 or foreign network transceiver 404 is atransceiver that is connected by wire to a router or a switch andperforms transmission and reception of packets. As the accessingtechnique for wired connection, any of the technologies that are widelyused in networks, such as Ethernet (registered trademark) and the likecan be used.

Storage 406 is a functional part for storing various kinds of data andprograms, in particular, includes a positional information managementtable 4062. Positional information management table 4062 stores a mobilenode in association with the position (address) of the correspondentmobile node. Here, the MIPv6 positional information containsidentification information on a mobile node and a care-of address gainedon the foreign network to which the mobile node connects.

FIG. 7 shows one example of the data configuration of positionalinformation management table 4062. As shown in FIG. 7, positionalinformation management table 4062 stores a mobile node and the position(address) of the correspondent mobile node. For example, the position ofmobile node 20 (HoA(P1::MN1)) is stored as to be PMA 30 andCoA(P2::MN1).

PMIPv6 processor 408 is a functional part that, when receiving aposition registration signal from PMA 30, registers the positionalinformation into positional information management table 4062 andtransmits a reply to PMA 30. Further, MIPv6 processor 410 is afunctional part that, when receiving a position registration signal frommobile node 20, registers the position into positional informationmanagement table 4062 and transmits a reply to mobile node 20.

The packet forwarder is a functional part for forwarding a packet basedon positional information management table 4062 stored in storage 406.This controls packet forwarding via PMIP network transceiver 402 orforeign network transceiver 404.

2. Processing Flow

[2.1 Position Registering Procedure]

[2.1.1 System Flow]

Next, the updating processes of the positional information in mobilenode 20, PMA 30, AR 10 and HA 40 in the network shown in FIG. 1 will bedescribed using the drawings.

To begin with, the position registering procedure of mobile node 20 willbe described based on the sequence diagram in FIG. 8. When detectionconnection to the PMIP network as a network-based mobility network,mobile node 20 makes an attachment request (procedure (a) in FIG. 8).

For example, mobile node 20, when it is started to operate, or power isturned on, sends an Association Request message for RRC (Radio Resourcecontrol) to PMA 30 to which it is going to attach, to make an attachmentrequest. At this point, mobile node 20 receives announcing informationfrom neighboring PMAs and selects PMA 30 based on the result ofperforming cell search. Specifically, the mobile node notifies theidentification information for itself to be identified, such as theglobal IP address, MAC address or UE-ID defined by specifications suchas 3GPP TS23.003V5.2.0, by the Association Request message so as to makean attachment request.

In PMA 30, wireless transceiver 302 receives the Association Request andregisters the identification information of mobile node 20 and the factthat mobile node 20 has attached to PMA 30, into attachment nodemanagement table 3062 of storage 306.

PMA 30 solves HA 40 at the destination to register based on theattachment request from mobile node 20 and transmits a positionregistering request to HA 40 (procedure (b) in FIG. 8). The method ofsolving HA 40 may be acquired from the apparatus for managing thecorrespondence between mobile node 20 and HA 40, such as an AAA serveretc., to which PMA 30 is connected, for example, or it is possible tosolve it by storing the receiver management table that previously holdsmanagement information of the correspondence between mobile node 20 andHA 40 into storage 306, in advance.

Specifically, PMA 30 notifies the identification information foridentifying mobile node 20, such as the global IP address, MAC addressor UE-ID, and an IP address for identifying PMA 30 that can be routedinside the PMIP network, as the positional information.

HA 40 receives the position registering request from PMA 30, andregisters the identification information of mobile node 20 associated toits positional information into positional information management table4062. The reply message includes the global IP address to be assigned tomobile node 20, or network prefix information of the global IP addressto be assigned to the mobile node.

When HA 40 registers the information on mobile node 20 into positionalinformation management table 4062, then it transmits a positionregistration reply to PMA 30 (procedure (c) in FIG. 8).

PMA 30, as receiving the reply from HA 40, registers into attachmentnode management table 3062 the forwarding destination of the packettransmitted from mobile node 20 to be the HA and so that a packetaddressed to the mobile node will be delivered to the mobile node.

PMA 30 makes a response to the attachment request from mobile node 20using RCC Association Response message or the like to the mobile node(procedure (d) in FIG. 8). The reply to the attachment request includesidentification information such as the IP address or MAC address of PMA30 so that mobile node 20 can set PMA 30 as the default router.

Mobile node 20 receives the attachment reply from first transceiver 202and registers PMA 30 as the attachment destination into addressmanagement table 2062. This identification information on PMA 30 doesnot need to be identical with the identification information on PMA 30registered in HA 40. For example, the IP address notified to HA 40 isthe IP address to be used for routing within the PMIP network, whereasthe IP address notified to the mobile node is the IP address which themobile node identifies as the default router.

As above, mobile node 20 performs connection to the PMIP networknetwork, in accordance with the procedures defined by PMIPv6. Further, aforwarding route is established between PMA 30 and HA 40, so that mobilenode 20 can perform communications by way of the forwarding routeestablished in the PMIP network.

Next, mobile node 20, while keeping connection to the PMIP network,performs connection to the foreign network using another transceiver.

Mobile node 20 makes another transceiver or second transceiver 204receive announcing information from the access router (AR 10) on thenetwork connected to it, to detect connection to the foreign network(procedure (e) in FIG. 8). Here, the announcing information transmittedfrom AR 10 is IPv6 router announcing information or the like, includinginformation on the network prefix of the connected network in additionto the MAC address and IP address of the access router.

Mobile node 20 generates its care-of address based on the network prefixinformation of the connected network of the received announcinginformation and transmits a position registering request to HA 40(procedure (f) in FIG. 8). The position registering request to betransmitted should include identification information of the mobile nodesuch as the home address, MAC address or UE-ID etc., and the care-ofaddress to be the positional information.

HA 40 receives the position registering request from mobile node 20 andregisters it into positional information management table 4062.Registered into positional information management table 4062 isidentification information of the mobile node such as the home address,MAC address or UE-ID etc., of mobile node 20 in association with thepositional information, i.e., the care-of address. As the aforementionedpositional information management table 4062, the same one that is usedat the time of position registration in the PMIP network may be used. Asa result, HA 40 can handle mobile node 20 having a single home addressby managing a plurality of positional information at the same time, thecare-of address as the positional information in the foreign network andPMA 30 as the positional information in the home link or the PMIPnetwork.

HA 40, after registration into positional information management table4062, transmits a position registration reply to mobile node 20(procedure (g) in FIG. 8).

Mobile node 20 receives the position registration reply from HA 40 andmanages the care-of address or home address and the address of HA 40 asthe position managing apparatus, with address management table 2062.

In the example where conventional PMIPv6 and MIPv6 are combined, in HA40, when a position registering request based on MIPv6 as shown inprocedure (f) in FIG. 8 is received in the state where PMIPvregistration is being performed, the positional information of PMIPv6 asthe home link is deleted and the positional registration based on theMIPv6 request is performed. Specifically, when the position registeringrequest by procedure (f) in FIG. 8 is received, the positionalinformation of the PMIP network in positional information managementtable 4062 is deleted and the positional information based on MIPv6 isregistered.

In the HA 40 in the present embodiment, the positional information ofthe PMIP network and the positional information based on the MIPv6 areregistered simultaneously in the positional information managementtable.

That is, it is the conventional practice that when HA 40 that managesconnection to the home link as the PMIP network receives a connectionrequest from the foreign link, the HA cuts connection to the home linkand permits connection to the foreign link. However, the HA 40 of thepresent embodiment manages both the connection information withoutcutting connection to the home link.

Also, in the example where conventional PMIPv6 and MIPv6 are combined,when position registration is performed in mobile node 20 based on MIPv6by means of another transceiver in the state where the mobile node isbeing connected to the PMIP network, the information on connection tothe PMIP network is deleted at the time of position registering, thenposition registration is performed from the foreign network based onMIPv6. Specifically, when the information on the attachment to the PMIPnetwork is deleted in address management table 2062, and a positionregistering request is transmitted to HA 40. However, in the presentembodiment, mobile node 20 holds the position registration informationfor both the PMIP network and the foreign network at the same time. Thatis, both the information of attachment to the PMIP network and theinformation of registration to HA 40 using the care-of address obtainedthrough the foreign network will be registered at the same time.

Accordingly, mobile node 20 connected to the packet communication systemin the present embodiment will perform positional registration from theforeign link without cutting off the connection with the home link tomanage both connection information.

In the state where mobile node 20 is being connected to the PMIPnetwork, HA 40 which has received the positional registration to theforeign network can keep both the positional information on the homelink and on the foreign link. However, in order to permit disconnectionfrom the home link as in the conventional manner when a request forconnection to the foreign link is made, information that indicateseither disconnection or simultaneous connection may be newly included tothe position registration information in the foreign link, whereby it ispossible for HA 40 to determine whether HA 40 manages a plurality ofpositional information for the mobile node or whether it deletes theholding information and performs new registration, in accordance withthe request from mobile node 20.

Specifically, the position registering request in procedure (f) in FIG.8 is added with a flag and is transmitted. Here, the flag is to be usedto determine whether the connection information in the home link shouldbe deleted.

Similarly, in the case where, while the mobile node is being connectedfrom a foreign link based on MIPv6, it makes a request for attachment tothe PMIP network to perform position registering to HA 40 through PMA30, HA 40 can perform a plurality of position registration in accordancewith the request from PMA 30 as stated above. However, it is alsopossible to cut off the connection to the foreign link and establishconnection to the home link as performed conventionally.

Accordingly, mobile node 20 transmits an attachment request includingthe information that shows either cutoff or simultaneous connection, toPMA 30. Further, PMA 30 transmits a position registering requestincluding the information indicating whether the cutoff has been done orsimultaneous connection is being established, to HA 40. HA 40 is able todetermine whether it manages a plurality of positional information formobile node 20 or whether it deletes the holding information andperforms new registration, in accordance with the request from mobilenode 20.

Specifically, the attachment request in procedure (a) in FIG. 8 is addedwith a flag and is transmitted. This flag is used to determine whetherthe connection information on the foreign network should be deleted. Inprocedure (b) in FIG. 8, PMA 30 adds the flag included in the attachmentrequest to the position registering request to be transmitted to HA 40and sends it.

Though the present embodiment was described taking an example in whichconnection to the foreign network is achieved after connection with thePMIP network, it goes without saying that connection to the PMIP networkmay be achieved after connection with the foreign network.

[2.1.2 Mobile Node's Processing Flow]

Next, the operation of mobile node 20 in the position registeringprocedure will be described using an operation flow. First, FIGS. 9 and10 are charts for illustrating the process related to positionregistering at mobile node 20

When mobile node 20 detects the fact that it has moved from one networkto another (Step S102; Yes), it is checked whether the packet receivedat the time of detection is one based on PMIPv6 or one based on MIPv6(Step S104).

Herein, when it is determined that the received packet is one that isbased on PMIPv6 (Step S106; Yes), it is checked whether updating shouldbe done by registering a plurality of positional information (StepS108).

Here, if updating is performed by registering the plurality ofpositional information (Step S108; Yes), a flag that indicates thatupdating needs to be done by the plurality of registration is added(Step S110). Then, an attachment request to the PMIP network istransmitted to PMA 30 (Step S112).

On the other hand, when it is determined that the packet detected at thetime of detection of movement is one that is not based on PMIPv6 (StepS106; No), it is determined that the packet is one based on MIPv6.Further, if updating is performed by registering the plurality ofpositional information (Step S120; Yes), a flag that indicates thatupdating needs to be done by the plurality of registration is added(Step S122). Then, a position registering request for the position inthe foreign network is transmitted to HA 40 (Step S124).

Subsequently, it is checked whether there has been reception of anattachment reply from the PMIP network or PMA 30 (Step S202) or whetherthere has been reception of a reply based on MIPv6 from HA 30 (StepS204).

Herein, when reception of an attachment reply has been received (StepS202; Yes/procedure (d) in FIG. 8) or when reception of a positionregistration reply has been received (Step S202; No→Step S204;Yes/procedure (g) in FIG. 8), it is checked whether the receivedattachment reply reception or position registration reply receptionincludes the flag so as to determine whether a plurality of positionalinformation (addresses) are registered (Step S206). Here, if it has beendetermined that updating is performed by registering the plurality ofpositional information (addresses) thanks to inclusion of the flag (StepS206; Yes), positional information (address) is added to addressmanagement table 2062. On the other hand, if it has been determined thatupdating is not performed by registering the plurality of positionalinformation (addresses) thanks to non-inclusion of the flag (Step S206;No), positional information (address) in address management table 2062is updated and stored.

[2.1.3 HA's Processing Flow]

Next, the operation of HA 40 when a mobile node is registered will bedescribed using an operation flow in FIG. 11.

First, HA 40 receives a position registering request (Step S302). Here,there are cases in which the position registering request is demandedfrom PMA 30 (procedure (b) in FIG. 8) and in which it is demanded frommobile node 20 (procedure (f) in FIG. 8).

Next, HA 40 determines whether it is necessary to register a pluralityof positional information that is demanded to be registered (Step S304).That is, it is determined whether there is the predetermined flag in theposition registering request signal. If there is the flag, it isdetermined that the plurality of positional information should beregistered, so that the position is additionally registered intopositional information management table 4062 (Step S304; Yes→Step S306).On the other hand, if there is no flag in the position registeringrequest signal, the positional information stored in positionalinformation management table 4062 is updated (Step S304; No→Step S308).

When completing position registering, HA 40 transmits a positionregistration reply (Step S310). Here, the position registration reply istransmitted to PMA 30 (procedure (c) in FIG. 8) and mobile node 20(procedure (g) in FIG. 8).

[2.2 Packet Forwarding Procedure]

[2.2.1 System Flow]

Next, communication between mobile node 20 connected to the PMIP networkand a foreign network and a communication terminal 50 connected to theforeign network will be described using the drawings. FIG. 12 is adiagram showing the scheme of a mobile communication system. Asdescribed heretofore, mobile node 20 includes a plurality oftransceivers, one connecting to the PMIP network and the other to theforeign link. The PMIP network is the home link for mobile node 20, andmovement of mobile node 20 changing PMAs inside PMIP network is donebased on PMIPv6. On the other hand, the node is connected to the foreignnetwork by the other transceiver, and movement of the node by changingARs in the foreign network is done based on MIPv6. Position registeringfor simultaneous use to both is realized in the method described above.

First, the sequence diagram in FIG. 13 is a chart for illustrating theoverall flow of the packet forwarding procedure. FIG. 14 is a diagramschematically showing how packets are forwarded.

To begin with, a forwarding route has been established between PMA 30and HA 40. This forwarding route is a forwarding path by way of the PMIPnetwork. Established further between HA 40 and mobile node 20 is aforwarding route by way of AR 10. This forwarding route is a forwardingpath by way of the foreign network.

Though in the present embodiment, the process of a case in which apacket is transmitted from communication terminal 50 to mobile node 20and a reply to it is made will be described, it is of course possible tosimilarly handle the case in which a packet is transmitted from mobilenode 20 to communication terminal 50.

(Packet Forwarding Through PMIP Network)

First, a case where a packet is forwarded by way of the PMIP networkwill be described. When a packet is transmitted from communicationterminal 50 to mobile node 20, the packet is transmitted to HA 40(procedure (a) in FIG. 13). At this point, the sender in the IP headerof the packet is “communication terminal 50” and the receiver is “mobilenode 20” (FIG. 14(a)).

In this case, HA 40 is the point of connection between the PMIP networkand the foreign network, and is the only gateway router that announcesthe routing information on the home network prefix of the mobile node.Specifically, HA 40 announces the routing information to the foreignnetwork so that any packet addressed to the home prefix of the mobilenode can be delivered to itself, and any packet addressed from thecommunication terminal connected to the foreign network to the mobilenode is delivered to HA 40.

HA 40 determines whether the packet is forwarded by way of the PMIPnetwork or by way of the foreign network, and forwards the packet.Herein, if the packet is assumed to be forwarded through the PMIPnetwork, the packet is forwarded to PMA 30 (procedure (b) in FIG. 13).At this point, the sender in the IP header of the forwarded packet is“HA 40” and the receiver is “PMA 30” (FIG. 14(b)). The packet data shownin FIG. 14(a) is stored as the payload. Then PMA 30 transmits the packetreceived from HA 40 to the receiver or mobile node 20 (procedure (c) inFIG. 13).

Next, when a packet is transmitted from mobile node 20 to communicationterminal 50, the packet is transmitted to PMA 30 first (procedure (d) inFIG. 13). At this point, the sender in the IP header of the transmittedpacket is “mobile node 20” and the receiver is “communication terminal50” (FIG. 14(c)).

Subsequently, PMA 30 forwards the packet data received from mobile node20 to HA 40 (procedure (e) in FIG. 13). At this point, the sender in theIP header of the forwarded packet is “PMA 30” and the receiver is “HA40” (FIG. 14(d)). The packet data shown in FIG. 14(c) is stored as thepayload. Then HA 40 transmits the received packet to communicationterminal 50 (procedure (f) in FIG. 13).

(Packet Forwarding Through Foreign Network)

Next, a case where a packet is forwarded by way of a foreign networkwill be described. When a packet is transmitted from communicationterminal 50 to mobile node 20, the packet is transmitted to HA 40(procedure (g) in FIG. 13). At this point, the sender in the IP headerof the packet is “communication terminal 50” and the receiver is “mobilenode 20” (FIG. 15(a)).

Then, HA 40 determines whether the packet is delivered by way of thePMIP network or by way of the foreign network, and forwards the packet.Herein, if the packet is assumed to be forwarded through the foreignnetwork, the packet is transmitted to mobile node 20 by way of AR 10(procedure (h) in FIG. 13). At this point, the sender in the IP headerof the transmitted packet is “HA 40” and the receiver is “mobile node20”. Here, a care-of address (CoA) is set for mobile node 20.

Next, when a packet is transmitted from mobile node 20 to communicationterminal 50, the packet is transmitted to HA 40 first by way of AR 10(procedure (i) in FIG. 13). At this point, the sender in the IP headerof the transmitted packet is “mobile node 20” and the receiver is“communication terminal 50” (FIG. 15(c)), but when it is sent to HA 40,the original IP packet is stored as the payload. That is, the packet istransmitted by setting the care-of address (CoA) of “mobile node 20” asthe sender and HA 40 as the receiver. Then, HA 40 transmits the receivedpacket to communication terminal 50 (procedure (j) in FIG. 13).

[2.2.2 Mobile Node's Processing Flow]

Next, the operation of mobile node 20 in the packet forwarding procedurewill be described using an operation flow. FIG. 16 is a chart forillustrating the process when a packet in mobile node 20 is transmitted.

First, in mobile node 20, packet transmitter 212 creates a transmissionpacket (Step S402). Here, processor 200 checks the positionalinformation stored in address management table 2062 (Step S404). In thiscase, when a plurality of positional information have been registered inaddress management table 2062 (Step S406; Yes), one transmission routeis selected based on the positional information among them (Step S408).

Then, a transmission route is determined from the selected transmissionroute or one transmission route defined as the positional information(Step S406; No)(Step S410). At this point, if transmission is carriedout based on MIPv6 (Step S412; Yes), the packet is subjected to an MIPv6process and then transmitted (Step S414). As the method for determininga transmission route at Step S410, a method of determining it using therouting protocol based on prefixes can be considered as an example.

[2.2.3 HA's Processing Flow]

Next, the operation of HA 40 in the packet forwarding procedure will bedescribed using an operation flow. FIG. 17 is a chart for illustratingthe process when a packet is forwarded in HA 40.

First, the packet is received by PMIP network transceiver 402 or foreignnetwork transceiver 404 of HA 40 (Step S502). At this point, processor400 determines whether the receiver of the received packet is addressedto a mobile node that the HA 40 manages (Step S504).

If the packet is addressed to a mobile node that the HA 40 manages (StepS504; Yes), it checks the position of mobile node 20 (Step S506). Atthis point, if a plurality of positional information on mobile node 20have been registered in positional information management table 4062(Step S508; Yes), the forwarding route is selected based on one of thepositional information (Step S510). Then, the HA determines a forwardingroute (Step S512) based on the selected forwarding route or the oneforwarding route defined as the positional information (Step S508; No)so as to forward the packet (Step S514). As the method for determining atransmission route at Step S410, a method of determining it using therouting protocol in the network can be considered as an example.

As described heretofore, according to the present embodiment, mobilenode 20 includes a plurality of transceivers so that it is possible toconnect to the PMIP network as the home link through one transceiver andconnect to a foreign network through the other transceiver at the sametime. For the identifier of a single mobile node 20, HA 40 manages PMA30 as its positional information on the PMIP network, and at the sametime, manages its care-of address on the foreign network as the foreignnetwork positional information.

As a result, it is possible to establish a plurality of communicationroutes for a mobile node, hence select and use them depending on thepreferences of the communication terminal at the communication partnerside, communication data and the like.

3. Application Example

Application of the present invention enables construction of alarge-scale PMIP network operated by a carrier or the like as its homelink while permitting mobile node 20 to connect the carrier network anda WLAN as a hot spot or the like at the same time. Further, the mobilenode can perform communications using a single IP address in bothnetworks. As a result, it is possible for the carrier, for example toachieve control such that an application that the carrier wants to becommunicated through its own PMIP network is communicated by way of thePMIP network while an application that is regarded to be able to achievea higher throughput if it is distributed through access networks such asWLAN etc., is entrusted to communication by way of a foreign network.

For example, as shown in FIG. 18, communication between mobile node 1and mobile node 2 connected to the PMIP network can be performed withinthe PMIP network using the transmission route between the HA and PMA 1and the transmission route between the HA and PMA 2 while communicationbetween a communication terminal and mobile node 1 connected to theforeign network can be realized through the foreign network using thetransmission route designated by the care-of address which is used bythe HA and mobile node 1 to connect to the foreign network. This enablesan application such as voice communication between the subscribers ofthe carrier that operates the PMIP network to be executed by performingcommunication through the PMIP network, and a case when mobile node 1acquires contents from WEB servers connected to the foreign network byFTP or HTTP access, to be achieved by performing communication by way ofa foreign network.

Further, it is possible to achieve seamless handover by realizingmultiple connection at the same time. The conventional handoverprocedure in PMIP and MIPv6 is performed by switching one connection toanother. In contrast, application of the present invention enables amobile node to realize simultaneous connection as shown in FIG. 19,whereby it is possible to achieve handover in a seamless manner by onlyselecting the communication route of communication data afterestablishment of the connecting procedure. That is, it wasconventionally necessary to implement mobile detection, terminalauthentication and the like in addition to position registration andestablishment of a transmission route as shown in the sequence whenhandover is carried out. However, application of the present invention,in a condition that a plurality of them are completed, makes it possibleto achieve handover by updating only the information for selection of atransmission route of preferences and the like between the HA and themobile node.

The invention claimed is:
 1. A terminal apparatus comprising: a firsttransceiver configured to start a first communication routeestablishment procedure by transmitting control information requestingan establishment of a communication route; and a second transceiverconfigured to start a second communication route establishment procedureby transmitting control information requesting an establishment of acommunication route, wherein the first communication route establishmentprocedure is a procedure that a position managing apparatus registers atleast a first identification; the first identification indicates a firstdata transfer destination to which the position management apparatustransfers data addressed to a first IP address; the first IP address isused for communications by the terminal apparatus; the terminalapparatus establishes a first communication route with the positionmanaging apparatus over a first access system, based on the firstcommunication route establishment procedure; the second communicationroute establishment procedure is a procedure that the position managingapparatus registers at least a second identification; the secondidentification indicates a second data transfer destination to which theposition management apparatus transfers data addressed to the first IPaddress; the terminal apparatus establishes a second communication routewith the position managing apparatus over a second access system, basedon the second communication route establishment procedure; the terminalapparatus maintains simultaneously the first communication route and thesecond communication route, both of which are used for thecommunications using the first IP address; the terminal apparatusperforms the communications over either the first communication route orthe second communication route or both; and each data for thecommunications is routed at any single time over one communicationroute.
 2. The terminal apparatus according to claim 1, wherein the firstidentification is an IP address of a gateway apparatus connecting thefirst access system with a network, and the network includes at leastthe position management apparatus and the gateway apparatus.
 3. Theterminal apparatus according to claim 1, wherein in accordance with eachcommunication flow of the communications, route selection is performedfrom either the first communication route or the second communicationroute.
 4. A communication control method for a terminal apparatus, thecommunication control method comprising: starting a first communicationroute establishment procedure by transmitting control informationrequesting an establishment of a communication route, wherein the firstcommunication route establishment procedure is a procedure that aposition managing apparatus registers at least a first identification,the first identification indicates a first data transfer destination towhich the position management apparatus transfers data addressed to afirst IP address, and the first IP address is used for communications bythe terminal apparatus; establishing a first communication route withthe position managing apparatus over a first access system, based on thefirst communication route establishment procedure; starting a secondcommunication route establishment procedure by transmitting controlinformation requesting an establishment of a communication route,wherein the second communication route establishment procedure is aprocedure that the position managing apparatus registers at least asecond identification, and the second identification indicates a seconddata transfer destination to which the position management apparatustransfers data addressed to the first IP address; establishing a secondcommunication route with the position managing apparatus over a secondaccess system, based on the second communication route establishmentprocedure; maintaining simultaneously the first communication route andthe second communication route, both of which are used for thecommunications using the first IP address; and performing thecommunications over either the first communication route or the secondcommunication route or both, wherein each data for the communications isrouted at any single time over one communication route.
 5. Thecommunication control method according to claim 4, wherein the firstidentification is an IP address of a gateway apparatus connecting thefirst access system with a network, and the network includes at leastthe position management apparatus and the gateway apparatus.
 6. Thecommunication control method according to claim 4, wherein in accordancewith each communication flow of the communications, route selection isperformed from either the first communication route or the secondcommunication route.
 7. A position managing apparatus comprising: afirst transceiver configured to connect to a first access system; asecond transceiver configured to connect to a second access system; anda memory, wherein based on a first communication route establishmentprocedure initiated by a terminal apparatus, the initiation beingperformed by transmitting control information requesting anestablishment of a communication route, the position managing apparatusregisters at least a first identification into the memory: the firstidentification indicates a first data transfer destination to which theposition management apparatus transfers data addressed to a first IPaddress; the first IP address is used for communications by the terminalapparatus; the position managing apparatus establishes a firstcommunication route with the terminal apparatus over the first accesssystem, based on the first communication route establishment procedure;based on a second communication route establishment procedure initiatedby the terminal apparatus, the initiation being performed bytransmitting control information requesting an establishment of acommunication route, the position managing apparatus registers at leasta second identification into the memory; the second identificationindicates a second data transfer destination to which the positionmanagement apparatus transfers data addressed to the first IP address;the position managing apparatus establishes a second communication routewith the terminal apparatus over the second access system, based on thesecond communication route establishment procedure; the positionmanaging apparatus maintains simultaneously the first communicationroute and the second communication route, both of which are used for thecommunications using the first IP address; the position managingapparatus performs the communications over either the firstcommunication route or the second communication route or both; and eachdata for the communications is routed at any single time over onecommunication route.
 8. The position managing apparatus according toclaim 7, wherein the first identification is an IP address of a gatewayapparatus connecting the first access system with a network, and thenetwork includes at least the position management apparatus and thegateway apparatus.
 9. The position managing apparatus according to claim7, wherein in accordance with each communication flow of thecommunications, route selection is performed from either the firstcommunication route or the second communication route.
 10. Acommunication control method for a position managing apparatus, thecommunication control method comprising: based on a first communicationroute establishment procedure initiated by a terminal apparatus, theinitiation being performed by transmitting control informationrequesting an establishment of a communication route, registering atleast a first identification, wherein the first identification indicatesa first data transfer destination to which the position managementapparatus transfers data addressed to a first IP address, and the firstIP address is used for communications by the terminal apparatus;establishing a first communication route with the terminal apparatusover a first access system, based on the first communication routeestablishment procedure; based on a second communication routeestablishment procedure initiated by the terminal apparatus, theinitiation being performed by transmitting control informationrequesting an establishment of a communication route, registering atleast a second identification, wherein the second identificationindicates a second data transfer destination to which the positionmanagement apparatus transfers data addressed to the first IP address;establishing a second communication route with the terminal apparatusover a second access system, based on the second communication routeestablishment procedure; maintaining simultaneously the firstcommunication route and the second communication route, both of whichare used for the communications using the first IP address; andperforming the communications over either the first communication routeor the second communication route or both, and each data for thecommunications is routed at any single time over one communicationroute.
 11. The communication control method according to claim 10,wherein the first identification is an IP address of a gateway apparatusconnecting the first access system with a network, and the networkincludes at least the position management apparatus and the gatewayapparatus.
 12. The communication control method according to claim 10,wherein in accordance with each communication flow of thecommunications, route selection is performed from either the firstcommunication route or the second communication route.